<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>
    #result {
      width: 200px;
      height: 100px;
      border: 1px solid #90b
    }
  </style>
</head>
<body>
  <button id="btn">点击发送请求</button>
  <button id="btn2">点击取消请求</button>
  


  <script>
    const btn = document.getElementById('btn')
    const btn2 = document.getElementById('btn2')
    let x = null
   
    btn.onclick = function () {
      x = new XMLHttpRequest()
      x.open('GET', 'http://127.0.0.1:8000/delay') 
      x.send()
    }


    // abort
    btn2.onclick = function () {
      if(x) {
        x.abort()
      }
     
    }





  </script>







</body>
</html>